Resonant Fragmentation of the Water Cation by Electron Impact: a Wave-Packet Study

We have investigated the dissociation of a resonant state that can be formed in low energy electron scattering from H2O+. We have chosen the second triplet resonance above the B & SIM;2A' ${{{\tilde{\rm {B}}}}\;<^>2 {\rm{A{<^>\prime}}}}$ (B & SIM;2B2) ${{\rm{(\tilde{B}}}\;<^>2 {\rm{B}}_2 )}$ state of H2O+ whose autoionization mainly produces H2O+ ( X & SIM;2A'' ${{{\tilde{\rm {X}}}}\;<^>2 {\rm{A{<^>\prime}{<^>\prime}}}}$ ). We have considered both dissociation of the resonant state itself, dissociative recombination (DR), or the dissociation of the H2O+ cation after autodetachment, dissociative excitation (DE). The time-evolution of a wave packet on the potential energy surfaces of the resonance and cationic states shows, for the initial conditions studied, that the probability for DR is about 38 % while the probability for DE is negligible.

Automated summary

We have investigated the dissociation of a resonant state in low energy electron scattering from H2O+. Specifically, we studied the second triplet resonance above the B & SIM;2A' ${{{\tilde{\rm {B}}}}\;<^>2 {\rm{A{<^>\prime}}}}$ (B & SIM;2B2) ${{\rm{(\tilde{B}}}\;<^>2 {\rm{B}}_2 )}}$ state of H2O+. Our results showed that the probability for dissociative recombination (DR) was about 38%, while the probability for dissociative excitation (DE) was negligible.